• Analytical Science and Technology
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• v.37 no.2
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• pp.87-97
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• 2024

The appropriate intake of fluoride (F^-) is beneficial to human health; however, the over-consumption can result in various potentially harmful effects. This study compared different colorimetric reagents, i.e., aluminium-xylenol orange (Al-XO), zirconium-xylenol orange (Zr-XO), and zirconium-alizarin red S (Zr-ARS), for fluoride measurements by the UV-Vis, in terms of reaction mechanisms, method sensitivity, and interferences from aluminium and ferric ions. The colorimetric procedures were optimized, and the analytical methods were evaluated. The goodness of linearity (R² > 0.998) was obtained for all three assays within the concentration range of 1.0-20.0 mg/L fluoride in deionized water, in which the method sensitivity followed the descending order of Zr-XO > Al-XO > Zr-ARS. The Zr-XO was applied for determining the fluoride in different tea extracts in water (90 ℃ and 60-minute-brewing) and black tea demonstrated the highest fluoride content (3.0-3.6 mg/L). The effects of brewing time and temperature on the release of fluoride in the tea extracts were also investigated, indicating these are critical factors for the fluoride extraction. This study highlighted the application potentials of the UV-Vis measurement as a simple, convenient, and cheap analytical approach and discussed different colorimetric reagents used for fluoride determination in tea extracts in the context that the UV-Vis spectrophotometers are commonly equipped in most laboratories.

• Korean Journal of Microbiology
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• v.41 no.4
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• pp.255-261
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• 2005

A 6.7kb DNA fragment containing the sprT gene encoding Streptomyces griseus trypsin (SGT) was cloned from Streptomyces griseus ATCC 10137, and the complete nucleotide sequence was determined. Nucleotide sequence and deduced amino acid or the EcoRI-HindIII fragment revealed the presence or the six complete ORFs containing the sprT gene and one incomplete ORF, which were named ORF1, SGT, ORF2, ORF3, ORF4, ORF5, and ORF6, respectively. ORF1 has homology with the oxidoreductases from several organisms. ORF2 and ORF3 show similarity with unknown proteins and transcription regulator that belongs to the ArsR family, respectively. ORF4 and ORF5 show homology with the peptidoglycan bound protein with LPXTG motif from Listeria monocytogenes and the membrane protein with transmembrane helix from several organisms, respectively. The last ORF, ORF6, shows homology with the lipoprotein from Streptomyces avermitilis.

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.370-372
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• 1995

A Phaffia rhodozyma chromosomal fragment (approximately 3.8 kb) capable of functioning as an origin for the replication of a kanamycin resistance ($Km^r$) plasmid in S. cerevisiae was isolated by the use of origin search plasmid, pHN134. In S. cerevisiae, transformation frequencies using the plasmid pHN134 containing an autonomously replicating sequence of P. rhodozyma was 450-580 CFU/$\mu g$ DNA. The stability of the recombinant plasmid were 16-19$\%$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.11
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• pp.1291-1297
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• 2014

This paper proposes integrated chassis control (ICC) with electronic stability control (ESC) and active rear steering (ARS). Direct yaw moment control is used to generate a control yaw moment. A weighted pseudo-inverse-based control allocation (WPCA) method is adopted to distribute the control yaw moment into tire forces, generated by ESC and ARS. Simulation-based tuning of variables weights in the WPCA is used to enhance the yaw moment distribution performance. Simulations using the vehicle simulation software $CarSim^{(R)}$ show that the proposed ICC is effective in improving maneuverability and lateral stability.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.763-770
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• 2012

Pseudomonas fluorescens 2112, isolated in Korea as an indigenous antagonistic bacteria, can produce 2,4-diacetylphloroglucinol (2,4-DAPG) and the siderophore pyoveridin2112 for the control of phytophthora blight of red-pepper. P. fluorescens 2112 was classified into a new genotype C among the 17 genotypes of 2,4-DAPG producers, by phlD restriction fragment length polymorphism (RFLP). The colonizing ability of P. fluorescens 2112 in pea rhizosphere was equal to the well-known pea colonizers, P. fluorescens Q8r1 (genotype D) and MVP1-4 (genotype P), after 6 cycling cultivations for 18 weeks. Four tested 2,4-DAPG-producing Pseudomonas spp. could colonize with about a 96% dominance ratio against total bacteria in pea rhizosphere. The strain P. fluorescens 2112 was as good a colonizer as other Pseudomonas spp. genotypes in pea plant growth-promoting rhizobacteria.

• Plant Resources
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• v.7 no.1
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• pp.77-86
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• 2004

The reduced ratio of red:far-red (R:FR) light acts as a measure of the proximity of competitors and plants can detect the potentially competing neighbor plants by perceiving reflected R:FR signals and initiate the response of “shade avoidance” before actual shading occurs. The phytochrome system is responsible for monitoring the changes in the R:FR and initiating the shade avoidance response. The response to low R:FR ratio was studied in a white aspen Populus alba clone ‘Bolleana’ using two filter systems: a clear plastic filter system that allows a R:FR ratio less than 1.0 to pass from adjacent border plant reflection; and a special commercial plastic that blocks FR light and creates a R:FR ratio above 3.0. The reduced R:FR signals enhanced the stem elongation in response to competition at the expense of relative stem diameter growth. Trees grown inside clear chambers were 27 ％ taller than trees grown inside the FR-blocking filter chambers. Stem taper of clear chamber trees was 16％ less than the FR-blocking filter trees. Low R:FR also induced 22％ more stem dry weight and 13％ greater petiole length per leaf compared to the FR-blocking filter trees. There were no statistically significant differences in leaf area, leaf number increment, and total dry weight between the two light filter treatments.

• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.104-109
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• 2016

In Korea, the government has invested the installation of artificial reefs (ARs) which deploying to enhance the restoration of marine environment and productivity on the coastal area at the part of 222,627ha, from 1971 to 2014 for 44 years. The number of ARs are gradually increasing, while their comparison and corelation analysis were not much studied. Therefore, this study is to analyse temporal variation of ARs which composed of concrete named the Horn triangle reefs were deployed at Pohang, Jangkil-ri, a depth of 5 to 7m, in 2003, was monitored 4 times from 2009 to 2011. In results, the biodiversity investigated that the dominant species was Mollusca Omphalius pfeifferi except in 2009. The different species mainly depend on spatial-temporal variation. In this type of study can be used to the R&D, management and government policy of ARs as well improving marine environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.386-394
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• 2016

This study investigates the validity of a Korean version of the Client Assessment Summary (CAS), which is a tool used to assess the recovery of alcoholics. We investigated the Korean CAS's suitability for use in assessing the scale of recovery scale of general alcoholics in Korea. In this study, we analyzed the data of 205 abstaining alcoholics in order to determine the validity of the Korean CAS. We undertook relationship analyses of CAS contents, reliability, and composition validity through factor analysis. In addition, we assessed ARS, abstinence period, abstinence self-efficacy, illness insight, and motivation change variables. The factor analysis results, performed after verification of content suitability by assessing 12 questions and 4 factors, confirmed the tool's composition validity, with the results showing relatively high values (R2 = 76.26%, communality ${\geq}0.6$, and KMO = 0.92). Moreover, internal consistency was acceptable (Cronbach's alpha = 0.92), and the correlations among ARS, abstinence self-efficacy, illness insight, and motivation change variables confirmed the validity of the Korean CAS. The proposed Korean CAS is expected to be useful when academically and clinically assessing the recovery of alcoholics; thereby, eventually contributing to successful recoveries from alcoholism.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.218-225
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• 1999

We isolated the ANRI fragment from Aspergillus nidulons that could autononlously replicate and enhance transformation efficiency about $10^4$ fold compared lo the integrative vector in Saccha,omgcer cerevisioe. In A. nidulans recombinant plasmid pLJ16-4.5 which carries the 4.5 kb EcoRI fragment of ANRI showed a 170-[old increase of transformation efficiency compared to the integrative vector pLJ16 and could be recovered from iransfonnants as an intact form. Estimated copy number of transforming plasmid pLJ16-4.5 was scored as 2 to 3 copies in transformed A. nidulans. Recoinbinant plasinid pILJ16-4.5 is inilotically unstable; being lost Irom 65% of aswual progeny of transformants on selective medium and 90% on complete medium. Southern analysis of transformant DNA showed that the pILJ16-4.5 is maintained in free form. The sequencing data showed that ANRl fragment was originated from mitochondiral DNA of A. nid~ilans and contained high AT content as much as 74.7%. One ARS consensus sequence (A/T)TTr4T(A/G)TTT(AiT). I I ARS-like sequence (agreement 10 of 11) and ABFl binding core consensus sequence (TCN7ACG). Also six gyrase binding core consensus sequence (YRTGNYNNY: y=C or T, R=A or G, N=A, G, C or T) of $\Phi$X174 and SV40 DNA and one b site (CACTTTACC) combining with gyrase in ColEl are shown. ANRl can be developed as a repl&ng plasinid for lransfoimation system in A. nirlulmis.

• Journal of Biosystems Engineering
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• v.31 no.6 s.119
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• pp.463-473
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• 2006

Automated sensing of soil macronutrients would allow more efficient mapping of soil nutrient spatial variability for variable-rate nutrient management. The capabilities of ion-selective electrodes for sensing macronutrients in soil extracts can be affected by the presence of other ions in the soil itself as well as by high concentrations of ions in soil extractants. Adoption of automated, on-the-go sensing of soil nutrients would be enhanced if a single extracting solution could be used for the concurrent extraction of multiple soil macronutrients. This paper reports on the ability of the Kelowna extractant to extract macronutrients (N, P, and K) from US Corn Belt soils and whether previously developed PVC-based nitrate and potassium ion-selective electrodes could determine the nitrate and potassium concentrations in soil extracts obtained using the Kelowna extractant. The extraction efficiencies of nitrate-N and phosphorus obtained with the Kelowna solution for seven US Corn Belt soils were comparable to those obtained with IM KCI and Mehlich III solutions when measured with automated ion and ICP analyzers, respectively. However, the potassium levels extracted with the Kelowna extractant were, on average, 42% less than those obtained with the Mehlich III solution. Nevertheless, it was expected that Kelowna could extract proportional amounts of potassium ion due to a strong linear relationship ($r^2$ = 0.96). Use of the PVC-based nitrate and potassium ion-selective electrodes proved to be feasible in measuring nitrate-N and potassium ions in Kelowna - soil extracts with almost 1 : 1 relationships and high coefficients of determination ($r^2$ > 0.9) between the levels of nitrate-N and potassium obtained with the ion-selective electrodes and standard analytical instruments.